Answer:
It protected the empire from invasion.
Explanation:
At that time, a conflict of interest exist in India in terms of the spread of Islam and Buddhism. (Asoka wanted to spread Buddhism while the kingdoms in middle east wanted to spread Islam).
As a result, Mauryan empire's territory often faced a lot of potential invasion from the empires that resided in the middle east. In order to handle this, Asoka created a group of spending army that could be mobilized to handle every scale of invasions. Mauryan Empire’s standing army consisted of 600,000 soldiers, 35,000 cavalry, and 6,500 war elephants that were directly led by Asoka.
